Automatic control device



March 16 1926.

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NaxweN H. H INVENTOR Patented Mar. 16, 1926.

i UNITED STATES' MAXWELL H. HILL, OF ROCHESTER, NEW YORK, ASSIGNOR T GLEASON WORKS, CFl

PATENT ortica.

ROCHESTER, NEW YORK, A CORPORATION 0F NEW yYOlEtK.

' AUTOMATIC CONTROL DEVICE.

Application filed July 27, 1925. Serial No. 46,387.

a citizen of the United States, residing at` Rochester, inthe county of Monroe and I State of New York, have invented a certainv new and useful Improvement in Automatic Control Devices, of which the following is a specification. The present invention rela-tes to van automatic control mechanism for machine tools.

Ihe primary object of the invention is to provide a control device which will be simple in operation, cheap to construct, and easy to keep in order.

AV further purpose ofthe invention is to provide a control device which can be set to operate after any determined number of minor operations of the machine tool upon which the control device is employed.

A further purpose of the invention is to provide a control device which may noty only be initially set to operate after a determined number of. minor operations of the machine tool upon which the control device is employed, but which will also automatically reset itself. I

Further objects of the invention will be 'apparent hereinafter from Jche specification and the claims.

While I have illustrated in the drawings appended hereto one preferred embodiment of my invention, it will be understood thaty the invention is capable of further modification within the limits of the disclosure and the scope of the appended claims.

In the drawings: c

Fig. l is a section through the casing of a control device constructed according to this invention, showing the operating parts in side elevation;

Fig. 2'is a sectional view taken generally at right angles to Fig. 1;-

Fig. 3 is av fragmentary perspective view, showing a portion of the exterior of the casing;

Fig. t is a detail, showing in plan, cery showing thersetting gear, indicator dial,y and ratchet wheel, and the connections therebetween.

The present invention relates to a controlv device of that type which includes asits basic element a member which has an operative connection with the machine tool upon which the control device is employed. The basic element is advanced step by step with each minor operation of the machine tool runtil it reaches a position where the work having been completed, it acts to vary yor completely stop the motion of the machine tool.

termined by the number of teeth to be cut on the blank, when through its operative connection with the machine, it will cause the machine to be stopped.

Referring to the drawings by numeral of reference, I have shown a ratchet wheel 5 rotatably mounted upon the stud 6 secured to the casing 7. This ratchet wheel is adapted to be advancedl one or more notches with each minor operation of the machine tool to which the control device is secured.. A pawl 8 pivotally mounted on 4 a pawl carrier 9, which is itself, pivotally mounted oni-the stud 10 secured to the casing, is employed to periodically advance the ratchet wheel. Any suitable ymeans may be employedy for rocking the pawl carrier 9 about its pivot l0 to bring the pawl 8 into engagement lwith the ratchet wheel to advance the same. As shown, this means comprises a plunger' 11 which is slidably mounted in a sleeve 12, preferably, formed integral with the casing 7. The plunger is ,operativelyV connected with a moving part of the machine tool and is adapted to be reciprocated in its sleeve with the completion 'of each minor operation of the machine tool to contact with the pawl carrier and to rock the same about its pivot 10. The connection betweenthe plunger and the machine tool may be of any desired nature and is not shown here as it forms no part of my invention. c

Pivotally mounted on the stud 10 along side the pawl carrier 9 is a lever arm 13.

The lever arm is normally held in the position shown in Fig. 1 by a spring 14: which .is secured at one end to the arm and at the other end to the casing. A catch 15 is pivotally secured to the levn arm 13 adjacent one end thercot. A trip arm 1G, which in the preferred en'ihodinu-mt of my invention, is pivotally secured to the pawl carrier 9, is adapted to engage the catch 15 on the lever arm 13, when the ratchet wheel has been advanced to a predetermined position, to rock the lever arm 13 about the pivot 19. For actuatingl the trip arm 1G into engagement with the catch 15 `on the lever arm 13 a pin 1T is provided. This pin is secured to the ratchet wheel so as to move therewith. lVhen the ratchet wheel has been advanced tar enough the pin 17 will engage the lower end ot the trip arm 16 moving tl'ielatter about its pivot until the portion 18 engages the catch This position is shown in Fig. 1. On the next movement et the plunger 11 and oil" the pawl carrier 9 the trip arm will force the lever l?) down against the action et the spring 1l. This movement of the lever arm is employed to effect a change in operation of the machine.

This movement of the lever arm may be utilized mechanically or electrically. A. chain, shown at 19 may be connected directly to or by a. link 2t) with the movable member 1B. The chain can be used to con trol a belt shifting device or other mechanism to automatically stop the machine or to otherwise change the operation of the machine. Instead of a chain connection any suitable type of linkage may be employed for the same purpose. The movable member 13 may also it' desired, be used to control the operation of the machine through some electrical device such as the limit switch 30. In the embodiment shown the limit `switch is thrown by the catch 15. To insure sufli cient time for the stoppingr of the machine after the completion of the operations on the work, where the control device is used to actnate an automatic stop mechanism, I have found it preferable to so arrange the parts `that the switch 3l) will be thrown on the return movement ol the lever 18 under actuat-ion ot the spring let instead of on the downward movement under actuation of the trip arm 1G. To accomplish this, the arm 21 of the limit switch carries a lugr 22:3 which is pivotcd on the arm for movement in one direction only. The catch 15 is provided on its rear end with a notch On the down stroke of the lever 13 the `catch rocks the lugr about its pivot 2t without moving the arm el the switch. On the re turn stroke oiI the lever 13 under actuation of the spring 14.-, the notch Q2 on the catch 15 engages the lun,r Q3 and thus throws the switch. i

Ordinarily Athe control device of this invention will be so designed as to operate either through a mechanical connection or an electrical connection. For the purpose ot illustrating` the manner in which this invention operates, however', I have shown both a mechanical connection 2() and an electriczl connection 39 between the control device and the machine.

As already stated, the control device ot this invention will preferably be so con structed that it may be set to operate atteithe completion ol any desired number of operations of the machine. In the preferred embodiment of the invention, the means for accomplishine,l this include a gear 25, an indicator dial 26, and a coil springl 27. The spring 27 is connected at one end by the pin 529 with the gea r 25 and at the other end with the indicator dial by the pin 29. A pin 31 secured to the ratchet wheel 5 and inserted in an aperture 32 in the indicator dial serves to connect the ratchet wheel and dial for movement together. The gear wheel is provided with a stop and the springl 27 is so arranged as to constantly urge the pin 31 to :return to the stop 35. This arrangement is employed for setting the ratchet wheel initially and for insuring its return to its initial setting; alter each operation oli the control device.

To set the ratchet wheel. initially the gear wheel Q5 may be rotated by a worm mounted on a spindle 35 which is journalcd in the casing` and which is provided at its outer end with a knurled nut 3G by means ot which |the worm may be rotated. llVhen the gear wheel is rotated. the spring 27 forces the indicator dial and the ratchet wheel to follow it, as already described. The indicator dial may be provided with any suitable graduations which may be read against the index pointer 37 on the casing. In a gear cutting` machine the ratchet wheel will be set according;I to the number oit teeth which are to be cut upon the blank.

As previously stated the ratchet wheel is advanced step by step by means of the pawl 8. To retain the ratchet wheel in its ad vanced position against the action ot the coil spring 2T, the dog 38 is provided. This dog may be an ordinary screw which is threaded into the lever arm lll adjacent one end. The dog' 38 is normally retained in position by the spring 14.

It' desired the plunger 11 may be threaded to adjnstably carry a nut l() and a lock-nut 4 1. By adjusting' these nnts the stroke ot the plunger can be adjusted so that itwill move the pawl carrier 9 a distance which will advance the ratchet wheel one or more teeth as desired at each stroke ot Athe plunger. The spring 39 which is' secured to the pawl carrier 9 at one end and to the casing 7 at the other end serves to hold the pawl normally out of engagement with the ratclr et Wheel. rlhis spring is strong enough to return the plunger 11 to the position shown in Fig. 1 after each stroke.

The operation of the device is as Jfollows: The ratchet wheel will be initially set by the worm 34 and worm wheel 25. Eachtime the machine tool completes a minor peration, as the cutting ot a tooth or the boring of a hole, some movable part ot the machine, as a lug on a reciprocating or oscillating bed, will move the plunger 11. rllhe plunger will rock the pawl carrier 9 about its pivot 10 and actuate the .pawl 8 into engagement with the ratchet wheel 5 -to advance the same one or more notches.- As the ratchet wheel moves the pin 1? moves .with it. lll/hen the ratchet wheel has advanced to the position shown inFig. 1, the pin 17 will contact with the trip arm 16 and force the same into engagement with the catch 15 secured to the lever 13. On the next stroke ot the plunger 11,the rocking of the pawl carrier 9 will 'force the lever arm 13 down against the action ot the spring 14. l/Vhen the lever arm is rocked down the dog 33 releases the ratchet Wheel and a coil spring returns the ratchet wheel to its initial setting which is determined by the position of the stop 33 on the gear wheel 25. When the lever arm is rocked down it also pulls down the linlr 20 and chain 19. Where the electrical. connection is employed, as already explained, the limit swi-tch is thrown on the return of the lever arm to normal position under actual tion of the spring 14E.

ln changing the setting of the ratchet wheel and dial, occasion sometimesl arises lor changing from a lower to a higher setting. There this is done it has been found best in practice to set a little beyond the desired marlr on the dial and position the ratchet wheel accurately by returning the pin 31 against the stop through actuation of the coil spring 27. To allow the coil spring to act the dog 3S can be released Jronrthe ratchet wheel by pushing down the lever 13. A lug l2 is provided on the lever arm 13 tor this purpose. This lug projects through an opening in the casingand the lever arm can 'be manually operated by pushing on this lug.

`While I have illustrated a preferred embodiment of my invention, it will be understood that the invention is capable of further modication within the limits of the disclosure and the scope ot the appended claims. rlhis application is intended'to cover any variations, uses, or adaptations of my invention, following, in general, the principles ot the invention and including such departures from the present disclosure as come within known or customary machine shop practice and as may be applied to the essential teatures hereinbetore set forth and as fall Within the limits ot the appended claims.

said pawl for movement therewith andV means carried by the ratchet Wheel for actuating said trip means into engagement with said movable member to move the same when the ratchet wheel reaches a position determined by its initial setting.

2. In an automatic control device, a ratchet wheel, apawl carrier, a pawl mounted on the carrier and adapted to advance said ratchet wheel, a trip arm pivotally mounted on the pawl carrier tor movement therewith', a movable member, a catch on said movable member, and means lifted to the ratchet wheel for actuatine` said trip arm into engagement with said catchwhen the ratchet wheel has been advanced to a predetermined position.

3. In an automatic control device, a ratchet wheel, a gear member, a stop on the gear member, a projection on the ratchet wheel, a coil spring connecting the gear member and ratchet wheel and urging the projection on the ratchet wheel to return to said stop, indicating means, means tor moving said gear member to initially set said ratchet wheel, a pawl for advancing said ratchet wheel, a dog for retaining said ratchet Wheel in its advanced position, a-

movable member, and means adapted to move said movable member when the ratchet wheel has been advanced to a position determined by its initial setting, said movable member and dog being operatively connected whereby the movable member is actuated and the dog released simultaneously.

el. In an automatic control device, a ratchet wheel, `an indicator dial connected to said ratchet wheel, means for initially setting said ratchet wheel, means urging said ratchet wheel and indicator dial to return to their initial setting, a pawl adapted to advance said ratchet Wheel, a dog normally holding said ratchet wheel in its advanced position, a trip lever, and means on the ratchet wheel adapted to actuate said trip arm into engagement with said dog to release the same when said ratchet wheel has.

been advanced to a position determined by its initial setting.

5.1n an automatic control device, a ratchet wheel, means for initially setting said ratchet wheel, a coil spring normally urging said ratchet wheel to return to its initial setting, a pawl carrier, a pawl mounted on the carrier, for advancing the ratchet wheel, a movable member, a dog normally holding said ratchet wheel in its advanced position, a trip arm pivotally mounted on the parti carrier, a catch on the movable member and meant; on the rntehet wheel for actuating' Said trip arm into engagement with said catch when the ratchet Wheel has been advanced to a ponition determined by ite` initial getting.

ln an automatic. control device, a caning, ay ratchet wheel rotatablliyv mounted in mid meine', an indicator dial connected to said ratchet wheel, a war member, a stop on the ,era r member` :t spring normally urging,l the rahfhrt wheel to return to Said Stop, nnans tor moving;` thc rear member to initially position eaid ratchet wheel, a pivotable dotT normali)r holding;` the ratchet wheel against the artica o'l said Spring. means projecting; throneh the easing ior reciting' said dog, n pam adapted to advance the ratchet wheel, and mean@1 adapted to be actuated into engagement with Said dog' to relcaac the neme when Said ratchet wheel hns; been ad,'aneed to a poi-:ition determined b v its initial netting.

T. ln an automatic control device, a ratchet wheel, a gear member, a stop on the gear member, a` projection on the ratchet wheel, a coil spring connecting the gear member and the ratchet wheel and urging the projection on the ratchet wheel to return to Said Stop, indicating menne, means for moving said gear member to initially Het said ratchet wheel, a pawl carrier, a pawl mounted on said carrier for advancing` the ratchet wheel, a movable member, means connected to said movable member ttor normail)7 holding` said ratchet Wheel in its advanced position, ay trip arm pivotally mounted on the pawl zarrier, a catch on the movable member and means on the ratchet wheel 'for actuating Said trip arm into engagement with said catch when the ratchet wheel has been advanced to a` ifnedetermined poaition.

In an automatic control device, a ratchet Wheel, a. gear member, a Stop on the ,gear member, a projection on the ratchet wheel, means connecting the gear member :nid ratchet wheel and urging the projection on the ratchet Wheel to return to said stop, means :for movinsoir said gear member to initially set the ratchet Wheel, zt pawl for aclvaneing said ratchet wheel, n movable dop,` normally holding the ratchet Wheel in its ad `'aneed position, and means adapted to be actuated when the ratchet Wheel has been advanced to :L predetermined position to move Said dog' and release said ratchet Wheel.

MAXVELL H. HILL. 

